Chaperone protein SurA may be necessary for the secretion of BrkA in Escherichia coli BW25113 during the stationary phase

Abstract

BrkA is a type Va autotransporter protein native to Bordetella pertussis that plays a critical role in evading the host immune response. The surface expression of BrkA, which is facilitated by passage through its own β-barrel domain, is critical for adhesion, cellular invasion, and serum resistance. Although periplasmic chaperones are known to facilitate autotransporter secretion, the specific proteins involved in BrkA secretion at particular growth phases remain unclear. This study explores the role of the chaperone protein SurA in the secretion of the autotransporter BrkA during the stationary phase in Escherichia coli. We aimed to determine BrkA expression during the stationary phase in ΔsurA mutant via immunoblotting. We also performed a growth curve assay comparing the ΔsurA mutant to the wild type. Our results suggest that SurA may be necessary for the secretion of BrkA during the stationary phase. These findings highlight the need to further explore phase-dependent functions of chaperones involved in BrkA secretion.